Microcatheter navigation through the clot: does size matter?

2018 ◽  
Vol 11 (3) ◽  
pp. 271-274 ◽  
Author(s):  
Jildaz Caroff ◽  
Robert M King ◽  
Rose Arslanian ◽  
Miklos Marosfoi ◽  
Erin T Langan ◽  
...  

BackgroundDespite high recanalization rates achieved with endovascular treatment of acute ischemic strokes, around 50% of eligible patients will not achieve a good outcome. Parameters that may determine patient outcomes include: time from puncture to recanalization, the collateral status, the anesthesia regimen, blood pressure management, and distal emboli. Characterization of distal emboli generated during mechanical thrombectomy has been performed in previous studies.ObjectiveTo further investigate the risk of distal embolization associated with microcatheter navigation across the clot.MethodsA contrast-enhanced clot analog was used in an in vitro model that mimicked a middle cerebral artery occlusion within a complete circle of Willis vascular replica. The clot was crossed with one of the following microcatheters: Pro18, XT-27 or 3MAX. The emboli generated during the procedure were collected and measured.ResultsThe use of Pro18 and XT-27 resulted in a significant reduction of visible particles (size ≥500 µm) as compared with the 3MAX catheter (P<0.003). For the size range between 8 and 200 µm, there was a trend for Pro18 to generate fewer particles (−18%) than XT-27 but without statistical significance (P>0.05). In comparison with previously published data, acquired under the same conditions, it was found that the clot crossing maneuver accounts approximately for 12% of the total number of small emboli (<200 µm) induced during a stent retriever-mediated mechanical thrombectomy procedure via a balloon guide catheter.ConclusionsThe clot crossing maneuver has a significant effect on the total number of small particles induced during mechanical thrombectomy. Smaller microcatheter sizes should be favored when possible.

2020 ◽  
Vol 12 (10) ◽  
pp. 1002-1007
Author(s):  
Sarah Johnson ◽  
Ray McCarthy ◽  
Brian Fahy ◽  
Oana Madalina Mereuta ◽  
Seán Fitzgerald ◽  
...  

​BackgroundCalcified cerebral emboli (CCEs) are a rare cause of acute ischemic stroke (AIS) and are frequently associated with poor outcomes. The presence of dense calcified material enables reliable identification of CCEs using non-contrast CT. However, recanalization rates with the available mechanical thrombectomy (MT) devices remain low.ObjectiveTo recreate a large vessel occlusion involving a CCE using an in vitro silicone model of the intracranial vessels and to demonstrate the feasability of this model to test different endovascular strategies to recanalize an occlusion of the M1 segment of the middle cerebral artery (MCA).​MethodsAn in vitro model was developed to evaluate different endovascular treatment approaches using contemporary devices in the M1 segment of the MCA. The in vitro model consisted of a CCE analog placed in a silicone neurovascular model. Development of an appropriate CCE analog was based on characterization of human calcified tissues that represent likely sources of CCEs. Feasibility of the model was demonstrated in a small number of MT devices using four common procedural techniques.​ResultsCCE analogs were developed with similar mechanical behavior to that of ex vivo calcified material. The in vitro model was evaluated with various MT techniques and devices to show feasibility of the model. In this limited evaluation, the most successful retrieval approach was performed with a stent retriever combined with local aspiration through a distal access catheter, and importantly, with flow arrest and dual aspiration using a balloon guide catheter.​ConclusionCharacterization of calcified tissues, which are likely sources of CCEs, has shown that CCEs are considerably stiffer than thrombus. This highlights the need for a different in vitro AIS model for CCEs than those used for thromboemboli. Consequentially, an in vitro AIS model representative of a CCE occlusion in the M1 segment of the MCA has been developed.


2021 ◽  
pp. 197140092110193
Author(s):  
Mohamad Abdalkader ◽  
Anurag Sahoo ◽  
Julie G Shulman ◽  
Elie Sader ◽  
Courtney Takahashi ◽  
...  

Background and purpose The diagnosis and management of acute fetal posterior cerebral artery occlusion are challenging. While endovascular treatment is established for anterior circulation large vessel occlusion stroke, little is known about the course of acute fetal posterior cerebral artery occlusions. We report the clinical course, radiological findings and management considerations of acute fetal posterior cerebral artery occlusion stroke. Methods We performed a retrospective review of consecutive patients presenting with acute large vessel occlusion who underwent cerebral angiogram and/or mechanical thrombectomy between January 2015 and January 2021. Patients diagnosed with fetal posterior cerebral artery occlusion were included. Demographic data, clinical presentation, imaging findings and management strategies were reviewed. Results Between January 2015 and January 2021, three patients with fetal posterior cerebral artery occlusion were identified from 400 patients who underwent angiogram and/or mechanical thrombectomy for acute stroke (0.75%). The first patient presented with concomitant fetal posterior cerebral artery and middle cerebral artery occlusions. Thrombectomy was performed with recanalisation of the fetal posterior cerebral artery but the patient died from malignant oedema. The second patient presented with isolated fetal posterior cerebral artery occlusion. No endovascular intervention was performed and the patient was disabled from malignant posterior cerebral artery infarct. The third patient presented with carotid occlusion and was found to have fetal posterior cerebral artery occlusion after internal carotid artery recanalisation. No further intervention was performed. The patient was left with residual contralateral homonymous hemianopia and mild left sided weakness. Conclusion Fetal posterior cerebral artery occlusion is a rare, but potentially disabling, cause of ischaemic stroke. Endovascular treatment is feasible. Further investigation is needed to compare the efficacy of medical versus endovascular management strategies.


2021 ◽  
pp. neurintsurg-2021-018017
Author(s):  
Andre Monteiro ◽  
Slah Khan ◽  
Muhammad Waqas ◽  
Rimal H Dossani ◽  
Nicco Ruggiero ◽  
...  

BackgroundAcute isolated posterior cerebral artery occlusions (aPCAOs) were excluded or under-represented in major randomized trials of mechanical thrombectomy (MT). The benefit of MT in comparison to intravenous tissue plasminogen activator (alteplase; IV-tPA) alone in these patients remains controversial and uncertain.MethodsWe performed a systematic search of PubMed, MEDLINE, and EMBASE databases for articles comparing MT with or without bridging IV-tPA and IV-tPA alone for aPCAO using keywords (‘posterior cerebral artery’, ‘thrombolysis’ and ‘thrombectomy’) with Boolean operators. Extracted data from patients reported in the studies were pooled into groups (MT vs IV-tPA alone) for comparison. Estimated rates for favorable outcome (modified Rankin scale score 0–2), symptomatic intracranial hemorrhage (sICH), and mortality were extracted.ResultsSeven articles (201 MT patients, 64 IV-tPA) were included, all retrospective. There was no statistically significant difference between pooled groups in median age, median presentation National Institutes of Health Stroke Scale (NIHSS) score, PCAO segment, and median time from symptom onset to puncture or needle. The recanalization rate was significantly higher in the MT group than the IV-tPA group (85.6% vs 53.1%, p<0.00001). Odds ratios for favorable outcome (OR 1.5, 95% CI 0.8 to 2.5), sICH (OR 1.1, 95% CI 0.2 to 5.5), and mortality (OR 1.4, 95% CI 0.5 to 3.6) did not significantly favor any modality.ConclusionsWe found no significant differences in odds of favorable outcome, sICH, and mortality in MT and IV-tPA in comparable aPCAO patients, despite superior MT recanalization rates. Equipoise remains regarding the optimal treatment modality for these patients.


2018 ◽  
Vol 683 ◽  
pp. 207-214 ◽  
Author(s):  
Kah Ni Tan ◽  
Rebecca Hood ◽  
Kirby Warren ◽  
Debbie Pepperall ◽  
Catalina Carrasco-Pozo ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1747 ◽  
Author(s):  
Nan Li ◽  
Lingling Feng ◽  
Yujun Tan ◽  
Yan Xiang ◽  
Ruoqi Zhang ◽  
...  

The dry root of Scutellaria baicalensis, has traditionally been applied in the treatment of cerebral ischemia in Chinese clinics. Baicalin (BA) is considered the key ingredient in it for the brain protection effects. The bioavailability of BA is very low because of its poor lipid and water solubility, which limits the therapeutic effects and clinical application. The aim of the present study was to develop a novel BA-loaded liposome (BA-LP) formulation to improve the drug lipophilicity and further to enhance the drug-concentration in the brain tissues. This study is also designed to investigate the pharmacokinetics of BA in the pathological conditions of stroke and evaluate the pharmacokinetic differences of BA caused by stroke after intravenous administration with BA and BA-LP. In this study, the novel BA-LP prepared in early stage were characterized by morphology, size, zeta potential, encapsulation rate and the in vitro release. The pharmacokinetics and biodistribution of BA and BA-LP were investigated by intravenous administration in rats with middle cerebral artery occlusion (MCAO) model and normal group respectively. BA-LP had a mean particle size of 160–190 nm, zeta potential of −5.7 mV, and encapsulation efficiency of 42 ± 1%. The BA-LP showed a sustained-release behavior, the in vitro drug-release kinetic model of BA-LP fit well with the biphasic dynamic model equation: Q = 1 − (60.12e0.56t − 59.08e0.0014t). Pharmacokinetic behavior in MCAO rats is not consistent with that of normal rats. The middle cerebral artery occlusion rats got higher Cmax and AUC0–t, which were about 1.5–2 times to normal rats both in BA and liposome groups. In addition, it got especially higher distribution in brain, while BA were not detected in brain tissues on normal rats. The Cmax and AUC0–t values were significantly greater with liposome than BA on both normal and MCAO rats. The tissue distribution behavior was significantly altered in the case of liposome administrated in comparison with BA, which the concentrations in the heart, liver, spleen, lungs and brain were all increased after administrated liposome, but decreased in kidneys. The TI values showed that the target of liposome was improved especially to heart, spleen and brain, and the brain’s target was higher in striatum and cerebellum. In conclusion, BA-LP might be a potential drug delivery system to improve the therapeutic efficacy of BA. In addition, these results also suggest that the pathological damages of ischemia-reperfusion have a significant impact on the pharmacokinetic traits of BA.


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